Elderly patients with leukemia can be successfully treated with aggressive chemotherapeutic regimens, although virtually all studies demonstrate decreasing remission rates with increasing age. However, the duration of complete remission is similar in younger and elderly patients if complete remission can be achieved. Therefore, the major limiting feature in successful therapy for older patients is the difficulty in achieving complete remission. One factor which may be related to the difficulty with achieving remission among elderly cancer patients is infection. The proposed project will determine among patients with leukemia treated at the UMCC during recent years the number and types of infection occurring among elderly and non-elderly patients with leukemia and will determine in the same patient population the case-fatality rates for elderly and non-elderly patients to determine if differences in the number, types, or case-fatality rate of infection may vary between elderly and non-elderly patients and may, therefore, be related to the decreased remission rate. The results from the proposed research can be utilized to design improved infection prevention and surveillance programs among elderly patient populations. Such programs might improve the remission and survival rates among elderly patients. However, first the pilot data are required.